Refactor Lockscreen fragment layouts

LinearLayout -> RelativeLayout
Also fixes issues on <xhdpi devices

Change-Id: I7b15728e21a705246526bc2867c1d860b03d93cb
Signed-off-by: Gergely Szell (sethyx) <szell@hu.ibm.com>
Merge "Refactor Lockscreen fragment layouts" into jb-mr1